Straight boats, or boats without coxswains, add a lot of enjoyment to the rowing experience. Rowers already have to worry about a ton of things, and not having a
cox in the boat adds a ton more. Despite the extra pressure, rowing a straight boat is really fun. This is especially true from the perspective of the
bowman, who takes the responsibility for most of the duties that are otherwise associated with the coxswain.
All sculling boats, with very few exceptions, are straight shells. Pairs and fours, both sweep boats, come in coxed and straight varieties. Rowers have to be responsible for their own motivation, technique, and steering. Steering is the biggest change from coxed to straight boats, because rowers in coxed boats are not used to looking around them and being aware of their surroundings.
Two things affect a boat's steering: relative pressure on port and starboard sides, and the position of the rudder, if one is present. Pairs, fours, and quads generally all have rudders, while singles and doubles generally don't. Instead of having hand-operated ropes to steer the boat like coxswains do, the rudder's steering cables will be connected to the shoe of the bowman or stroke. That rower will have to angle their foot in order to make the rudder move.
Since there are no rudders in singles and most doubles, all steering is done with pressure. Scullers have two oars, so they can adjust their position by changing how hard they pull on each oar, or how long the relative sides' strokes are. If they pull harder on their starboard oars, their bow will become pointed more towards port side, and vice versa. Even in boats with rudders, varying pressure helps the crew steer straight.
The main idea behind steering straight shells is to get the bow pointed at a certain spot that you'd like to aim for, called a point. That's very difficult to do when you're facing backwards and you have to worry about winding turns, other boats, wakes, bridge arches, and a myriad other hazards. And even once you've found a point, they typically don't last too long. Since the river (or lake, or whatever body of water the crew happens to be on) probably has many turns, the rowers have to change direction often. Bowmen should look over their outboard shoulder every three strokes or so, always on the drive. Turning around to see what's going on causes extraneous body movements, so it's best to look during the drive, when the oars are in the water and the boat is balanced well.
From boat to boat and crew to crew, steering techniques will differ. Quads typically have their rudder hooked up to the bow's shoes, and that is where the majority of the steering comes from. On the other end of the spectrum, pairs rely fairly heavily on pressure differences to steer the boat, partly because the effect of the rudder on the boat's balance is felt more strongly in smaller boats like the pair. The pair is notorious for being difficult to balance, because you rely completely on your pair partner. More incompetent fools flip the pair than any other boat.
Good communication is absolutely essential. Bow is responsible for the actions of the boat, so he calls all the shots. He says who rows when, at what pressure, calls drills, etc. If the rudder is not on his toe, the bowman tells the stroke to slide the rudder over to one side when necessary. If there is not good communication between those two, stroke will end up steering too much or not enough. All of the rowers in the boat should stay aware of what's going on, helping the crew stay pointed and making sure they don't crash into anything. Each rower has his niche in making the boat stay straight and powerful, so communication is extremely important in helping the boat move.
Straight boats, especially smaller ones, offer rowers the opportunity to learn good technique by their own discipline. When there's no cox there to yell at you when you do things wrong, you must focus in on moving the boat and not wasting energy or upsetting the boat's precious balance. As a result, you can try different things and find out what works best. My pair partner and I have done countless pause drills up and down the Charles River to improve our balance and timing, and now we are able to set our boat so well that it looks cleaner than the majority of eights we see. That refined technique translates directly into bigger boats like the eight, where your effect on the boat's balance and run are not as easily felt, but just as important.
Since steering is easy after a moderate amount of practice, and the crew will not have to drag around the extra weight of a coxswain, straight boats go faster than their coxed counterparts. Many rowing regattas feature competitions for straight boats. Rowing in straight boats does wonders for teamwork and technique. When you get out there and have to do everything yourself, you truly learn how to move a boat.